Thin section and critical point dried fracture label (new cytochemical methods developed in our laboratory) are used to determine the partition and distribution of glycophorin associated wheat germ agglutinin (WGA) binding sites over fractured membrane halves of human erythrocytes. Most WGA is found on exoplasmic halves in contrast with preferential labelling of Band 3 over protoplasmic halves by concanavalin A. We conclude that fracture process of transmembrane proteins is stochastic in nature and appears modulated by the relative expression of each transmembrane protein at either surface as well as by their association to components of the erythrocyte membrane skeleton.